Apparatus for winding up a web in rolls and a method for cutting off a length of the web

ABSTRACT

The invention provides a method and an apparatus for winding material. The apparatus includes first and second roll carriages that are each configured to support a roll shaft. At least one of the first and second roll carriages is configured to be rotated by a drive member. The apparatus also includes an engagement roller displaceable from a first engagement roller position where the traveling roller is free of a web to a second, different engagement roller position where the traveling roller is configured to engage the periphery of a roll of web material that is at least partially wound about the roll, a traveling roller displaceable from a first traveling roller position to a second traveling roller position and a cutter where the cutter is configured to cut through the web after the first roll carriage moves from a first roll carriage position to a second roll carriage position.

[0001] The invention relates to an apparatus for winding up a materialweb in rolls on roll shafts and also a method for, by operating thisapparatus, cutting off a free length of the web.

[0002] Such material webs, which for example could be air-laid fibrewebs, are generally produced continually in plants arranged in such away that it is not possible to change the production rate of the plantduring the winding-up process.

[0003] This fact is causing some problems in connection with rollshifting where the web is cut and a new winding-up operation is startedon an empty roll shaft while the web at the same time continuously issupplied to the winding-up apparatus.

[0004] Problems also are arising at rupture of the web or when startinga new production of web as the supply of the web from the web producingplant to the winding-up apparatus in these cases does not take place inaccordance with the usual winding-up cycles.

[0005] Many attempts have during the years been made for solving theseproblems. In these cases, the web roll being wound up is normallyconveyed from a start position to a finish position for thereby makingroom for a new, empty roll shaft brought in position for winding-up anew web roll.

[0006] The best result is obtained when the winding-up of the web rollis carried out by means of a centre drive, directly rotating the rollshaft, in combination with a periphery drive, acting on the periphery ofthe web roll.

[0007] In a known winding-up apparatus, the winding-up operation isstarted with a centre drive which, when the web roll has reached asuitable size, is taken over or is supplemented by a periphery drive inform of a belt drive placed below the roll.

[0008] In another known winding-up apparatus the centre drive is takenover or is supplemented by a periphery drive in form of a drive rollacting on the periphery of the web roll.

[0009] These known winding-up apparatus suffer, however, of the drawbackthat it, at e.g. rupture of the web or starting of a new web production,is difficult and complicated to start the winding-up on a new, emptyroll shaft as the apparatuses in such situations are not able to impartthe necessary web tension to the web to cause the new roll shaft tocatch the web. Neither is it possible manually to wrap the web aroundthe old web roll for continuing the winding-up of the web on this roll.

[0010] The object of the invention is to provide an apparatus of thekind named in the opening paragraph, which have a simple constructionand at rupture of the web or starting up of a new web production, easilyis able to start the winding-up of the web on a new roll shaft.

[0011] Another object of the invention is to provide an apparatus of thekind mentioned in the opening paragraph, which at rupture of the web orstarting up of a new web production, allows an operator manually to wrapthe web around the old web roll for continuing the winding-up on thisroll.

[0012] A third object of the invention is to provide a method of thekind mentioned in the opening paragraph for, by operating the apparatusaccording to the invention, cutting off a free length of the web.

[0013] These objects are, according to the invention, attained byproviding an apparatus serving for winding up a material web in rollsand comprising two roll carriages, each having supporting structures forsupporting the ends of a roll shaft and also rotating means for rotatingsaid shaft during operation, means for conveying each carriageto-and-fro between a start position where the winding-up of a roll ofweb on an empty shaft is started, and a finish position where thewinding up of the roll is finished, a first pressure roller beingdisplaceable between a first position where the roller is supporting theweb at a distance from an empty shaft on a carriage being in startposition and a second position where the roller is pressing the webagainst said shaft, a second pressure roller displaceable between astart position where the roller is free of the web and other positionsthan the start position where the roller is engaging the periphery of aweb roll partly or completely wound-up, a cutting knife which is placedin an area between the first and second pressure rollers and isdisplaceable between a first position at a distance from the web and asecond position where the knife has cut through the web, and means for,at roll exchanging, simultaneously or immediately after each other,displacing the first pressure roller and the cutting knife from thefirst to the second position.

[0014] A carriage with an old web roll can by means of this constructionadvantageously be conveyed towards its finish position without blockingfor the access to said web roll.

[0015] Another advantage consist in that it is possible to obtain ormaintain tension in the web after rupture of this such that a shift to anew shaft can be made in a controlled way.

[0016] Still another advantage consist in that an operator at rupture ofthe web manually is able to wrap the web around a not finished web rollfor continuing the winding-up such that the web rupture will be builtinto the web roll.

[0017] In a simple and expedient embodiment of the invention, the firstpressure roller is rotatably mounted on a pair of arms, which arepivotally mounted on a frame of the apparatus, while the second pressureroller is rotatably mounted on a second pair of arms, which arepivotally mounted on the first pair of arms and preferably concentricwith the rotating axis of the first pressure roller.

[0018] According to the invention the cutting knife could be pivotallymounted on the first—or second pair of arms and preferably concentricwith the rotating axis of the first—or second pressure roller,respectively.

[0019] It is possible to start a new winding-up operation in a safe andreliable way when the winding-up apparatus according to the invention iscomprising a wrapping device for, at roll exchanging, wrapping theleading edge of the cut web at least partly around the empty roll shaft.

[0020] This advantage could be further improved by means of an endlessbelt running over two rollers and arranged for being brought intocontact with the empty roll shaft at roll exchanging.

[0021] The second pressure roller could, according to the invention, bea driving roller for partially or completely rotating a roll of web,partly wound-up, by engaging the periphery of said roll.

[0022] Alternatively, the second roller could, according to theinvention, be a follower roller, whereby it advantageously is obtainedthat the roll can be tightened before roll exchanging.

[0023] The roll exchanging could, according to the invention, in an easyway be carried out automatically by means of a charging device having arotatable magazine for holding a number of empty roll shafts and apivotal charging arm for removing a roll shaft from the magazine andplacing it in the supporting structures of a roll carriage being in thestart position.

[0024] When starting a new web production or at rupture of the web, itcould be advantageous or even necessary to cut off a length of the webbefore starting the winding-up of the web in web rolls, for example ifthe length of web has defect in material.

[0025] This cutting operation could, according to the invention, becarried out by bringing the first pressure roller into its firstposition, the cutting knife into its first position, the second pressureroller into its first position or a position near this first position, alength of web past the second pressure roller, the second pressureroller to a position other than its first one, and the cutting knifeinto its second position.

[0026] The friction between the rotating second pressure roller and theweb will impart this with a tension sufficient for cutting the web. Saidfriction could be improved by means of a rubber surface on the secondpressure roller.

[0027] During the cutting-off process, there is a risk that said lengthof web will wound itself round the second pressure roller. This riskcould, according to the invention, be eliminated by acting on the lengthof web by a force, which e.g. could be jets of air, in an oppositedirection of the rotating direction of the second pressure roll.

[0028] The invention will be explained more fully by the followingdescription of an embodiment, which just serves as an example, withreference to the drawing, in which

[0029]FIG. 1 is a schematic view of an winding-up apparatus according tothe invention in one operation stage,

[0030]FIG. 2 shows the apparatus in another operation stage,

[0031]FIG. 3 shows the apparatus in a third operation stage,

[0032]FIG. 4 shows the apparatus in a forth operation stage,

[0033]FIG. 5 shows the apparatus in a fifth operation stage,

[0034]FIG. 6 shows, in a first operation stage, how a length of web iscut off by using the winding-up apparatus according to the invention,

[0035]FIG. 7 shows the same in a second operation stage, and

[0036]FIG. 8 shows the same in a third operation stage.

[0037]FIGS. 1-6 shows by way of example a winding-up apparatus accordingto the invention.

[0038] The apparatus has a frame (not shown) for mounting the differentcomponents of the apparatus, and it comprises two, known per se, rollcarriages, which in the drawing only are indicated by a new, empty rollshaft 1 and an old roll shaft 2 bearing a web roll 3.

[0039] Each carriage has supporting structures (not shown) forsupporting the ends of a roll shaft 1 or 2 and also rotating means (notshown) for rotating the shaft during operation.

[0040] The apparatus also has means (not shown) for conveying thecarriages between a start position where the winding-up of a roll of webon an empty shaft is started, and a finish position where the winding upof the web roll is finished.

[0041] As seen in e.g. FIG. 3, the start position is indicated by theposition of the new, empty roll shaft 1, while the finish position isindicated by the position of the roll shaft 2 carrying the finishedwound-up web roll 3.

[0042] The apparatus further comprises a first pressure roller 4, asecond pressure roller 5, a deflecting roller 6 and other deflectingrollers 7-12 for leading a web 13 into the apparatus in the direction ofthe arrow.

[0043] The first pressure roller 4 is rotatably mounted about an axis 14on a first pair of arms 15 which are pivotally mounted on the frame ofthe apparatus about an axis 16 concentric with the rotation axis of thedeflecting roller 6.

[0044] The second pressure roller 5 is rotatably mounted on a secondpair of arms 17, which are pivotally mounted on the first pair of arms15 about the axis 14 of the first pressure roller 4.

[0045] The apparatus also has driving means as e.g. pneumatic orhydraulic cylinders (not shown) for swinging the first—and second pairof arms 15 and 17 about their axis 16 and 14, respectively, in such away that the first pressure roller 4 is displaced between a firstposition at a distance from an new, empty shaft 1 in start position anda second position where the pressure roller 4 is pressing the web 13against said shaft 1, and the second pressure roller 5 is displacedbetween a start position where the pressure roller 5 is free of the web13 and other positions than the start position where the roller 5 isengaging the periphery of a web roll 3 partly or completely wound-up.

[0046] Between the first and second pressure rollers 4 and 5,respectively, is arranged a cutting knife 18, which by means of e.g.pneumatic or hydraulic cylinders (not shown) can be displaced between afirst position at a distance from the web and a second position wherethe knife has cut through the web.

[0047] The cutting knife 18 is, in the example shown in the FIGS. 1-6,pivotally mounted on the first pair of arms 15 about the rotating axis14 of the first pressure roller 4.

[0048] Alternatively, the cutting knife can be pivotally mounted on thesecond pair of arms 17 about the rotating axis 19 of the second pressureroller 5 whereby there will be a longer free end of web to be wrappedaround the new roll shaft 1 in start position than in the above namedcase. This situation is not shown in the drawing.

[0049] Said wrapping operation is carried out by means of a wrappingdevice 19, which in this case is pivotally mounted on the first pair ofarms 15 about the rotating axis 14 of the first pressure roller 4. Onthe wrapping device is, close to the knife 18, formed a curved surface20 for engaging the free end of the web 13 during the wrappingoperation.

[0050] An endless belt 21, running over two rollers 22 and 23,respectively, is provided for further improving the wrapping operationby being brought into contact with the new, empty roll shaft 1 at rollexchanging.

[0051] The apparatus also comprises a charging device consisting of arotatable magazine 24 for, in holders 25, holding a number of empty rollshafts, and a pivotal charging arm 26 for removing a roll shaft from themagazine and placing it in the supporting structures of a roll carriagebeing in the start position.

[0052] The apparatus is operating in the following way.

[0053] A web roll 3 is in FIG. 1 in winding-up position on a roll shaft2. The winding-up of the web roll is carried out by means of the centredrive and the periphery drive of the second pressure roller 5 mounted onthe second pair of arms 17 being in one of their other positions, whilethe first pressure roller 4 is in the first position. The secondpressure roller 5 being a driving roller.

[0054] In the magazine 24 is, by means of e.g. a crane (not shown),placed two empty roll shafts 1. The charging arm 26 is in position forcatching the lowest one of these shafts and the belt 21 has been swungup to a free position.

[0055] In FIG. 2 the web roll is nearly finished being wound up and thecharging arm 26 is placing a new, empty roll shaft 1 in the startposition.

[0056] In FIG. 3 the web roll is finished being wound up. The new, emptyroll shaft 1 is in start position. The first pressure roller 1 has beendisplaced from the first position to the second position, therebypressing the web 13 against the roll shaft 1. The cutting knife 18 hasbeen displaced from the first position to the second position, therebycutting the web 13. The leading edge of the web 13 has been wrappedsomewhat around the roll shaft 1 by means of the wrapping device 19 andthe endless belt 21 has been swung down the roll shaft 1 for furtherwrapping the web 13 around said shaft.

[0057] The second pressure roller 5 is, during the above namedoperations, in engagement with the periphery of the web roll 3 while thefirst pressure roller 4 engages the roll shaft 1 simultaneously oralmost simultaneously with the cutting operation which therefore can becarried out with the necessary tension in the web between the tworollers 4, 5 for cutting the web.

[0058] Normally, the web roll will be wound around a core in form of acardboard tube put on the roll shaft 1. On the cardboard is usuallyapplied a tape with an adhesive for securely bringing the web along whenstarting the winding-up of a new web roll on the rotating new roll shaft1.

[0059] By using conventional apparatuses, the tape or the adhesive onthe tape will be rubbed off, as the web in these cases is contacting therotating roll shaft before being cut.

[0060] This problem is avoided by using the apparatus of the inventionas the web 13 is now pressed against the roll shaft at the same momentas the web is cut and wrapped around said roll shaft.

[0061] The finished wound-up web roll has in FIG. 4 been removed bymeans of e.g. a crane (not shown) and a new web roll is in the beginningof the winding-up operation, which in this phase is carried out alone bymeans of the centre drive as the second pressure roller 2 is not inengagement with the periphery of the still small web roll.

[0062] The size of the small roll in FIG. 4 has in FIG. 5 increased somuch that the second pressure roller is able to engage the periphery ofthe web roll, now being acted on by means of both a centre drive and aperiphery drive.

[0063] During the winding-up of the web roll both the centre drive andthe periphery drive can be regulated in such a way that a web can bewound-up with driving forces which just conform to the characteristicsof that particular material web thereby securing a perfect quality ofthe web roll.

[0064] Thereby it is an advantage that the periphery drive is acted onthe web roll being wound up independent of the weight of this web roll.

[0065] The apparatus is constructed in such a way that an operator hasfree access to a web roll being wound up. At rupture of the web theoperator is therefore able to manually wrap the leading edge of the cutweb round the web roll for continuing the winding-up such that the webrupture will be built into the finished web roll.

[0066] In some cases it could be necessary to cut off a length of a web,for example when starting a new web production or when a length of theweb must be rejected owing to imperfections in the material.

[0067]FIGS. 6-9 show how this operation is carried out by using theapparatus according to the invention.

[0068] The second pressure roll 5 is in FIG. 6 in its start position andthe first pressure roll 4 is in its first position where it is notengaging a roll shaft. A free length of web is hanging over the firstpressure roller.

[0069] The second pressure roller 5 has in FIG. 7 been swung to a higherposition where it during the rotating is acting on the web with africtional force which will tend to twist the web round the secondpressure roller 5. This is, however, prevented by ejecting air jets 27against the back of the web.

[0070] As it appears from FIG. 8, said frictional force will cause asufficient tension in the web for cutting off said free length of web,which then can be removed and rejected.

[0071] The second pressure roller could advantageously have a rubberface for increasing the frictional force between the roller and the web.

[0072] In the embodiment described above, the second pressure roller wasa driving roller. In another embodiment, it could be a follower rollerwhereby the advantage is obtained that the web roll can be tightenedbefore roll shifting.

1-17. (Canceled) 18: An apparatus for winding up a material web in rollson roll shafts, comprising: two roll carriages, each having supportingstructures for supporting roll shafts thereon and a drive mechanism forrotating the roll shafts during operation, means for conveying eachcarriage to-and-fro between a start position where the winding-up of aroll of a web on an empty shaft is initiated, and a finish positionwhere the winding up of the roll is complete, a first pressure rollerdisplaceable between a first position where the roller is supporting theweb at a distance from an empty shaft on a roll carriage in the startposition and a second position where the first pressure roller urges theweb against the empty shaft, a second pressure roller displaceablebetween a start position where the roller is free of the web andpositions other than the start position where the second pressure rollerengages a periphery of a partly or completely wound-up web roll, acutting knife located between the first and second pressure rollers andbeing displaceable between a first position at a spaced distance fromthe web and a second position where the knife has cut through the web,and means for, at roll exchanging, simultaneously or sequentiallydisplacing the first pressure roller and the cutting knife from thefirst to the second position to transfer the web from the partly orcompletely wound-up web roll to an empty roll shaft. 19: The apparatusof claim 18, wherein the first pressure roller is rotatably mounted onat least one arm which is pivotally mounted on a frame. 20: Theapparatus of claim 19, wherein the second pressure roller is rotatablymounted on at least one arm which is pivotally mounted on the first arm.21: The apparatus of claim 20, wherein the first pressure roller isrotatably mounted on a pair of arms which are pivotally mounted on aframe, the second pressure roller is rotatably mounted on a second pairof arms which are pivotally mounted on the first pair of arms, and thesecond pair of arms defines a pivot axis that is concentric with theaxis of rotation of the first pressure roller. 22: The apparatus ofclaim 21, wherein the cutting knife is pivotally mounted on the firstpair of arms. 23: The apparatus of claim 22, wherein the cutting knifehas a pivot axis that is concentric with the rotating axis of the firstpressure roller. 24: The apparatus of claim 21, wherein the cuttingknife is pivotally mounted on the second pair of arms. 25: The apparatusof claim 24, wherein the cutting knife has a pivot axis that isconcentric with the rotating axis of the second pressure roller. 26: Theapparatus of claim 18, further comprising a wrapping device for wrappinga leading edge of the web at least partly around a new, empty roll shaftafter the web is cut. 27: The apparatus of claim 18, wherein the firstpressure roller is a driving roller. 28: The apparatus of claim 18,wherein the second pressure roller is a driving roller for rotating aroll of partially wound web by engaging the periphery of the roll. 29:The apparatus of claim 18, wherein the second pressure roller is afollower roller. 30: The apparatus of claim 18, further comprising atleast one endless belt operatively associated with two further rollersand arranged for being brought into contact with a new, empty roll shaftwhen the web is cut. 31: The apparatus of claim 18, further comprising acharging device having a rotatable magazine for holding a number ofempty roll shafts and a pivotal charging arm for removing a roll shafthaving a completely or partially wound web thereon and for providing anempty roll shaft in the start position. 32: A method for cutting off afree length of the web while operating an apparatus for winding-up amaterial web in rolls on roll shafts, which comprises: providing tworoll carriages, each having supporting structures for supporting rollshafts thereon and a drive mechanism for rotating the roll shafts duringoperation, conveying each carriage to-and-fro between a start positionwhere the winding-up of a roll of a web on an empty shaft is initiated,and a finish position where the winding up of the roll is complete,displacing a first pressure roller between a first position where theroller is supporting the web at a distance from an empty shaft on a rollcarriage in the start position and a second position where the firstpressure roller urges the web against the empty shaft, displacing asecond pressure roller between a start position where the roller is freeof the web and positions other than the start position where the secondpressure roller engages a periphery of a partly or completely wound-upweb roll, displacing a cutting knife between a first position at aspaced distance from the web and a second position where the knife cutsthrough the web, and simultaneously or sequentially displacing the firstpressure roller and the cutting knife from the first to the secondposition to transfer the web from the partly or completely wound-up webroll to an empty roll shaft. 33: The method of claim 32, wherein theweb, during cutting, is acted upon by a force having a directionopposite to the rotating direction of the second pressure roller. 34:The method of claim 33, wherein the force is provided by air jets.